Betelgeuse is the only star that glows red in the night sky. The average lifespan of a star is about 13.5 billion years (1,300 crore). Our sun is around 5.3 billion years old, halfway through its life. Betelgeuse on the other hand is a giant star, much bigger than that of our sun. It has exhausted almost all of its fuel and is nearing the end of its life.
Size Comparison With Our Sun
Our sun is a medium sized star that will turn into a red giant in another 5 billion years ( 500 crore). At that time, as a red giant, it will encompass the orbits of Mercury and Venus. Our earth will be uninhabitable as it will be stripped off its atmosphere and left burnt. Hey don’t worry, this won’t happen even in your great great grandson’s lifetime. The sun will remain a red giant for a million years. In this phase, it will burn its reserve fuel. After a million years, the outer layer of our star will fade away as a gaseous shell, thereby exposing its core. This event is known as a planetary nebula. The exposed core will appear as a glowing white dot known as a white dwarf.
However, Betelgeuse is a massive star which is more than 15 times the mass of our sun. Which means that the mass of the core will collapse and the star will explode into a supernova instead of forming a planetary nebula.
So When Will it Go Supernova?
Betelgeuse is currently a red giant that could go supernova any time. Astronomers are studying the star closely, however, they are not able to determine when it will explode. When it does, the people of earth will experience a breathtaking view of the explosion. The sky will light up and for a brief period it will seem like there are two suns present. The light emitted by the explosion will be so bright that it will engulf a part of the sky.
You may wonder whether we might get destroyed by the explosion. You need not give it a thought as the star is 642 light years away.
Where is it?
On a clear night sky, Betelgeuse will appear as a red star. In fact, it is the only star that appears as a red dot. You can spot it easily as it is a part of the Orion constellation. Refer to the image below.
Space Age 